include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Sat, 06 Aug 2011 01:21:24 -0400
changeset 5604 e2ad06c52c65
parent 5582 1281a3f1f0a6
child 5993 c9cb52d6d864
permissions -rw-r--r--
Updated configure for new changes in configure.in
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /**
    23  *  \file SDL_rwops.h
    24  *  
    25  *  This file provides a general interface for SDL to read and write
    26  *  data streams.  It can easily be extended to files, memory, etc.
    27  */
    28 
    29 #ifndef _SDL_rwops_h
    30 #define _SDL_rwops_h
    31 
    32 #include "SDL_stdinc.h"
    33 #include "SDL_error.h"
    34 
    35 #include "begin_code.h"
    36 /* Set up for C function definitions, even when using C++ */
    37 #ifdef __cplusplus
    38 /* *INDENT-OFF* */
    39 extern "C" {
    40 /* *INDENT-ON* */
    41 #endif
    42 
    43 /**
    44  * This is the read/write operation structure -- very basic.
    45  */
    46 typedef struct SDL_RWops
    47 {
    48     /**
    49      *  Seek to \c offset relative to \c whence, one of stdio's whence values:
    50      *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
    51      *  
    52      *  \return the final offset in the data stream.
    53      */
    54     long (SDLCALL * seek) (struct SDL_RWops * context, long offset,
    55                            int whence);
    56 
    57     /**
    58      *  Read up to \c maxnum objects each of size \c size from the data
    59      *  stream to the area pointed at by \c ptr.
    60      *  
    61      *  \return the number of objects read, or 0 at error or end of file.
    62      */
    63     size_t(SDLCALL * read) (struct SDL_RWops * context, void *ptr,
    64                             size_t size, size_t maxnum);
    65 
    66     /**
    67      *  Write exactly \c num objects each of size \c size from the area
    68      *  pointed at by \c ptr to data stream.
    69      *  
    70      *  \return the number of objects written, or 0 at error or end of file.
    71      */
    72     size_t(SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
    73                              size_t size, size_t num);
    74 
    75     /**
    76      *  Close and free an allocated SDL_RWops structure.
    77      *  
    78      *  \return 0 if successful or -1 on write error when flushing data.
    79      */
    80     int (SDLCALL * close) (struct SDL_RWops * context);
    81 
    82     Uint32 type;
    83     union
    84     {
    85 #if defined(ANDROID)
    86         struct
    87         {
    88             void *fileName;
    89             void *fileNameRef;
    90             void *inputStream;
    91             void *inputStreamRef;
    92             void *skipMethod;
    93             void *readableByteChannel;
    94             void *readableByteChannelRef;
    95             void *readMethod;
    96             long position;
    97             int size;
    98         } androidio;
    99 #elif defined(__WIN32__)
   100         struct
   101         {
   102             SDL_bool append;
   103             void *h;
   104             struct
   105             {
   106                 void *data;
   107                 size_t size;
   108                 size_t left;
   109             } buffer;
   110         } windowsio;
   111 #endif
   112 
   113 #ifdef HAVE_STDIO_H
   114         struct
   115         {
   116             SDL_bool autoclose;
   117             FILE *fp;
   118         } stdio;
   119 #endif
   120         struct
   121         {
   122             Uint8 *base;
   123             Uint8 *here;
   124             Uint8 *stop;
   125         } mem;
   126         struct
   127         {
   128             void *data1;
   129         } unknown;
   130     } hidden;
   131 
   132 } SDL_RWops;
   133 
   134 
   135 /**
   136  *  \name RWFrom functions
   137  *  
   138  *  Functions to create SDL_RWops structures from various data streams.
   139  */
   140 /*@{*/
   141 
   142 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
   143                                                   const char *mode);
   144 
   145 #ifdef HAVE_STDIO_H
   146 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
   147                                                 SDL_bool autoclose);
   148 #else
   149 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
   150                                                 SDL_bool autoclose);
   151 #endif
   152 
   153 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
   154 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
   155                                                       int size);
   156 
   157 /*@}*//*RWFrom functions*/
   158 
   159 
   160 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
   161 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
   162 
   163 #define RW_SEEK_SET	0       /**< Seek from the beginning of data */
   164 #define RW_SEEK_CUR	1       /**< Seek relative to current read point */
   165 #define RW_SEEK_END	2       /**< Seek relative to the end of data */
   166 
   167 /**
   168  *  \name Read/write macros
   169  *  
   170  *  Macros to easily read and write from an SDL_RWops structure.
   171  */
   172 /*@{*/
   173 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
   174 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
   175 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
   176 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   177 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   178 /*@}*//*Read/write macros*/
   179 
   180 
   181 /** 
   182  *  \name Read endian functions
   183  *  
   184  *  Read an item of the specified endianness and return in native format.
   185  */
   186 /*@{*/
   187 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
   188 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
   189 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
   190 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
   191 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
   192 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
   193 /*@}*//*Read endian functions*/
   194 
   195 /** 
   196  *  \name Write endian functions
   197  *  
   198  *  Write an item of native format to the specified endianness.
   199  */
   200 /*@{*/
   201 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
   202 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
   203 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
   204 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
   205 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
   206 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
   207 /*@}*//*Write endian functions*/
   208 
   209 
   210 /* Ends C function definitions when using C++ */
   211 #ifdef __cplusplus
   212 /* *INDENT-OFF* */
   213 }
   214 /* *INDENT-ON* */
   215 #endif
   216 #include "close_code.h"
   217 
   218 #endif /* _SDL_rwops_h */
   219 
   220 /* vi: set ts=4 sw=4 expandtab: */